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J.R.THOM'AS. v PRESSURE BAR FOR PLANING MACHINES.

(No Model.)

No. 429,395. Patented June 3,1890.

UNITED, STATES PATENT OFFICE.

JOHN R. THOMAS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE S. A. WVOODS MACHINE COMPANY, OF SAME PLACE.

PRESSURE-BAR FOR PLANlNG-MACHINES.

SPECIFICATION forming part of Letters Patent No. 429,395, dated June 3, 1890.

Application filed October 29, 1889. Serial No. 328,542. (No model.)

To all whom it may concern.-

Be it known that I, J OHN R. THOMAS, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Pressure-Bars for Planing-Machines, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention has for its object to improve the construction of that class of pressure-bar having a yielding spring-plate for a chipbreaker. In this class of pressure-bar the spring-plate bearing upon the board close to the point where the latter is attacked by the blades of the cutter-head is subjected to very great strain, for the unplaned and uneven surface of the board has to travel under the said plate before arriving at the cutter-head.

To obviate undue and injurious strains or blows on the spring-plate constituting the chip-breaker by the ends of the boards to be planed as they are introduced under the said spring-plate, I have provided the pressure-bar with a lifting projection, against and under which the end of each board to be planed must pass before arriving at the said springplate, the latter being so located with relation to the said projection and to the lip of the pressure-bar, which prevents undue rising of the spring-plate, that the said springplate is enabled to have a movement to only the extent needed to properly conform to usual inequalities at the surface of usual sawed boards.

In practice the spring-plate, when not resting on a board, stands normally at a slight" distance from the lip referred to; but when in use the said plate is borne upwardly from end to end against the smooth unbroken under side of the said lip.

It sometimes happens that a small chip or piece of wood gets caught between the sprin plate and the lip referred to, in which event, to enable the said chip to be readily removed, I have provided the spring-plate with a series of holes, of less area, however, than the holes shown in the spring-plate represented in United States Patent No. 146,500, on which the invention herein contained is an improvement.

My invention consists, essentially, in the combination, with a pressure-bar having a lifting projection and a lip extended horizontally toward the cutter-head, of a spring-plate attached to the said pressure-bar and occupying a position between the said projection and the said lip, as will be described.

Figure 1 is a plan View of a pressure-bar embodying my invention; Fig. 2, a section in the line to, Fig. 1, the said figure showing by dotted lines the path of movement of the cutting-edge of the blades of the cutter-head, and also the usual feed-roller; Fig. 3, a view of the pressure-bar shown in Fig. 1, looking at it in the direction of the arrow, Fig. 2; and Fig. 4 is a detail showing the spring-plate chip-breaker.

The pressure-bar composed, as shown, of the side pieces a at, having tapped hubs a and the cross-beam b, are and may be of usual construction, except that I have shown the cross-beam of the pressure-bar as extended downwardly or provided with a lifting proj ection b, the said projection being preferably integral with the said cross-beam, the lower end of the said projection against which the end of an incoming board strikes being carried down substantially in the line of the lower side of the lip o, the shank c of which is attached to the cross-beam b by suitable bolts 0 The angular spring-plate cl, constituting the shank of the lip c has its under surface located slightly below the projection 12, and its upper surface located slightly below the under surface of the said lip, the space be tween the said plate and the said lip being but very slight, so that when the said plate acts on a board on its way to the cutter-head the upper smooth side of the said plate con tacts with the under smooth side of the said lip, and the said contact will be uniform and the space between the plate and lip will be wholly closed at the end of the lip, provided there is no unusual or abnormal projection or hard spot in the board being planed. The lifting projection 19' prevents any injury to the plate d as the boards are introduced un der the said plate, and as a result the said plate is not bent at the angle 2, and not be- (Z, secured between the said lip and the said ing bent the elasticity of the said plate is projection, substantially as described. kept uniform from end to end, which would 2. The pressure-bar having a lifting pro- 20 not be the case if the said .plate should be jection 1') arranged in advance of the spring- 5 bent or indented by the blow of an incoming plate, to be acted upon by an incoming board, board. and the lip a, combined with the spring-plate The plate has a series of openings 3, out (Z, secured between the said lip and the said through which any pieces of chips maybe disprojection, the said plate having a series of z 5 charged if such pieces should happen to get holes 3, to operate substantially as described.

I0 into the space between the plate and lip. In testimony whereof I have signed my The usual feed-roller eand adj usting-scrcw name to this specification in the presence of f are shown by dotted lines, Fig. 2. two subscribing Witnesses.

I claim v t 1. The pressure-bar having a lifting pro- JOHN IHIOMAS' I 5 jection 1) arranged in advance of the spring- \Vitnesses:

plate to be acted upon by an incoming board, JAMES ROBERTS,

and the lip 0, combined with the spring-plate THOMAS R. MILLER. 

